The vine mealy bug has been pestering winegrape growers in Lodi for more than a decade, but the Lodi Winegrape Commission and pest control experts are fighting back with a wasp that savagely attacks the nuisance.
In vineyards scattered across town, Kent Daane, an entomologist from University of California, Berkeley, and a team of researchers released a predator to the bug with the hopes of curbing Lodi's population of the vine mealy bug in the coming years.
"Can you feel the mealy bugs leaving the vineyard in fear?" Daane said after releasing 2,000 of the predators native to Spain into a Zinfandel vineyard on Peltier Road.
While he was joking about the instantaneous mass-migration of pests away from the vineyard, his sentiments are accurate. The wasp seeks out the mealy bugs and eradicates them in a fashion akin to a science fiction movie.
"The female adult lays eggs in the mealy bug and then they eat it from the inside out when they hatch," said Daane. "It's like the movie 'Alien.'"
The wasp, Anagyrus pseudococci, is about the size of a gnat and harmless to humans. They were contained in glass vials before researchers emptied in area vineyards Thursday. One hundred females and dozens of males were in each individual vial. Five thousand female wasps were deposited in local vineyards during the day.
The vine mealy bug originated in Mexico, where it targeted table grapes, Daane said. It came to California in the early 1990s at a juicing facility in Bakersfield before working its way up the Central Valley. It first appeared in Lodi in 1998, he said.
"It attaches to everything," he said. "It attaches to harvest equipment, birds, rats, and even your arm hair if you're picking grapes."
Since the pest is so prevalent, a quarantine is not issued in vineyards where it's discovered, Chavoor said.
Once a pest latches onto a plant, it goes to work attacking the grapes. Like aphids, the bugs secrete a substance that other insects find delicious, he said.
"The ants end up eating the grapes and will protect the mealy bugs," Chavoor said.
The natural approach to pest management falls in line with the commission's "Lodi Rules" sustainable approach to winegrowing. "Lodi Rules" is a program that outlines standards and practices for growers in the region.
Biological control — using a pest's natural enemies to protect crops — is part of the "Lodi Rules" approach to Integrated Pest Management, said Walt Chavoor, the sustainable viticultural director for the commission.
The commission is sponsoring the program with hopes it can help decrease the vine mealy bug population in coming years, he said.
Daane will check the vineyards in two weeks to see how the process is going. He will be able to gauge success by looking for "mummified" carcasses of mealy bugs that have been eaten from the inside out, he said.
While the process is effective in similar climates around the globe, Daane said it takes time.
"This is inoculation, not augmentation," he said. "This today is for next year's harvest and the years after."
Contact reporter Jordan Guinn at firstname.lastname@example.org.